Introduction: The association between respiratory syncytial virus (RSV) infections and long-term respiratory sequelae has long been recognized. It is estimated that individuals with a history of RSV bronchiolitis have 2- to 12-fold higher risk of developing asthma. Although this risk tends to decrease with age, persistent airway obstruction and hyperresponsiveness are observed even 30 years after RSV infection.
Evidence acquisition: Our data search strategy was designed to address the following questions: What is the epidemiological evidence available on the association between RSV infection and long-term respiratory morbidity? What are the potential pathogenic pathways linking RSV infection to long-term respiratory morbidity? Are there any host genetic backgrounds that can predispose to both severe RSV lower respiratory tract infection and asthma? Are antiviral therapies and RSV prevention measures effective in reducing respiratory morbidities?
Evidence synthesis: This article reviews the recent scientific literature on the epidemiological association and pathogenic links between early RSV infection and long-term respiratory morbidities.
Conclusions: Nowadays, asthma is increasingly considered a heterogeneous disease, caused by interactions between several host and environmental factors. Understanding the specific causative role of respiratory viruses, and the pathogenic mechanisms through which bronchiolitis predisposes to asthma, is a challenging, but essential starting point for the development of prevention and treatment strategies potentially capable of preserving lung function.